Recent multi-country analyses of average pregnancy and duration of delivery in the United States, the United Kingdom, and the Netherlands suggest that the United States can improve maternal care outcomes by reducing medical interventions at the time of delivery. The United States has alarmingly high maternal and infant mortality rates compared to other rich and European countries, and maternal health continues to deteriorate.
A new study by researchers from Boston University's School of Public Health and Harvard-affiliated Beth Israel Deaconess Medical Center reveals the possible impact of hospital organizational structure and staffing in obstetric care in the United States on the delivery process and poor birth outcomes.
The study, published in PLOS ONE, compared patterns of pregnancy and the timing of delivery at home and in hospitals in three high-income countries, which differed in obstetric care: the United States relied primarily on obstetricians and clinical interventions, while the United Kingdom and the Netherlands predominantly used midwives for low-intervention care.
The results show that between 1990 and 2020, the average length of pregnancy in the United States steadily decreased by more than half a week, from 39.1 weeks to 38.5 weeks, and that the length of pregnancy in the United States was shorter on average than in England and the Netherlands. In 2020, only 23% of births in the US occurred at 40 weeks or more, compared to 44% in the Netherlands and 40% in the UK. The gestational age pattern for home births is the same in all three countries.
In the three countries, the researchers also examined the timing of home and hospital vaginal delivery by hour of the day, then repeated this analysis and limited the comparison to hospital vaginal delivery without interventions that could change the timing, such as induction or augmentation.
In England and the Netherlands, births at home and in hospital occur at similar times of the day, peaking between 1 a.m. and 6 a.m.
But in the United States, the timing of labor in the two settings is markedly different: the peak period of home birth is the same as the peak period of home birth in other countries. In contrast, hospital births — even those without intervention that could affect natural time patterns — basically took place during the standard working hours of clinical staff, from 8 a.m. to 5 p.m.
The paper is the first international study to use a large dataset to compare gestational age and time of birth in three high-income countries; Most previous studies have focused on data from individual hospitals or countries. Given the superior birth outcomes in the UK and the Netherlands, the authors say their findings suggest that obstetric care models in the United States could benefit from an organizational shift that places less emphasis on active clinical labor management and instead allows the labor process to take place naturally.
"Our multi-country analysis shows that the United States is an outlier in terms of gestational age distribution and timing of delivery in low-intervention hospitals," said study leader and corresponding author Dr. Eugene Declercq, professor of community health sciences at BUSPH. "One lesson to be learned from countries with more positive maternal outcomes than the U.S. is that hospital staffing and operational plans are more in line with the natural pattern of time and gestational age rather than trying to adapt time to organizational needs."
The study included nationally representative and publicly available birth data from the three countries, including more than 3.8 million births in the United States and 156,000 births in the Netherlands in 2014, and more than 56,000 births in the United Kingdom from 2008 to 2010. The researchers examined the timing of delivery in homes and hospitals that occurred between 37 and 42 weeks.
"Each system is perfectly designed to produce the results it gets," said Dr. Neel Shah, senior author of the study, chief medical officer at the Maven Clinic and visiting scientist at BIDMC. "The shockingly poor results of the U.S. maternal health care system call for greater attention to its design. Our research suggests that U.S. hospitals may be designed with clinicians' convenience centered rather than the needs of birthers in mind, compared to other high-income countries."